THURSDAY, Nov. 4 (HealthDay News) -- Variations in an immune
system protein explain the rare ability of some HIV-infected people
to remain healthy without having to take any medications,
The finding could help in efforts to develop new HIV treatments
and vaccines, the study authors pointed out.
The immune system is able to suppress viral replication and keep
viral load at extremely low levels in about one in 300 HIV
patients. These patients are called HIV controllers.
U.S. researchers analyzed the genomes of about 1,000 HIV
controllers and 2,600 HIV patients with progressive infection. The
controllers had variations in five amino acids in a protein called
HLA-B, which alerts the immune system to the presence of
The study was conducted by researchers at the Ragon Institute of
Massachusetts General Hospital, MIT and Harvard, and from the Broad
Institute of MIT and Harvard.
"We found that, of the three billion nucleotides in the human genome, just a handful make the difference between those who can stay healthy in spite of HIV infection and those who, without treatment, will develop AIDS," co-senior author Dr. Bruce Walker, director of the Ragon Institute, said in a Ragon Institute/Broad Institute news release.
"Earlier studies had showed that certain genes involved with the HLA system were important for HIV control. But they couldn't tell us exactly which genes were involved and how they produced this difference," co-senior author Paul de Bakker, of the Broad Institute and Brigham and Women's Hospital in Boston, said in the news release. "Our findings take us not only to a specific protein, but to a part of that protein that is essential to its function."
The study is published online Nov. 4 in the journal
"HIV is slowly revealing its secrets, and this is yet another," Walker said. "Knowing how an effective immune response against HIV is generated is an important step toward replicating that response with a vaccine. We have a long way to go before translating this into a treatment for infected patients and a vaccine to prevent infection, but we are an important step closer."
The U.S. National Institute of Allergy and Infectious Diseases
has more about